Proximity sensor devices (also commonly called touch sensor devices) are widely used in a variety of electronic systems. A proximity sensor device typically includes a sensing region, often demarked by a surface, in which input objects can be detected. Example input objects include fingers, styli, and the like. The proximity sensor device can utilize one or more sensors based on capacitive, resistive, inductive, optical, acoustic and/or other technology. Further, the proximity sensor device may determine the presence, location and/or motion of a single input object in the sensing region, or of multiple input objects simultaneously in the sensor region.
The proximity sensor device can be used to enable control of an associated electronic system. For example, proximity sensor devices are often used as input devices for larger computing systems, including: notebook computers and desktop computers. Proximity sensor devices are also often used in smaller systems, including: handheld systems such as personal digital assistants (PDAs), remote controls, and communication systems such as wireless telephones and text messaging systems. Increasingly, proximity sensor devices are used in media systems, such as CD, DVD, MP3, video or other media recorders or players. The proximity sensor device can be integral or peripheral to the computing system with which it interacts.
One issue with some past proximity sensor devices is that the sensor devices are limited to receiving input with objects that are at or very near the surface. Specifically, most proximity sensor devices can accurately determine location and/or motion of objects that are either right at the surface, or very near to the surface. However, when the objects are farther away from the surface the device the accuracy degrades, and most devices cannot reliably respond to such objects, and thus simply ignore such objects. This limits the flexibility and usability of the sensor device. Thus, there exists a need for improvements in proximity sensor device that improves device flexibility and usability.